coresight: Drop atomics in connection refcounts

These belong to the device being enabled or disabled and are only ever
used inside the device's spinlock. Remove the atomics to not imply that
there are any other concurrent accesses.

If atomics were necessary I don't think they would have been enough
anyway. There would be nothing to prevent an enable or disable running
concurrently if not for the spinlock.

Signed-off-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20241128121414.2425119-1-james.clark@linaro.org

Author: james-c-linaro

drivers/hwtracing/coresight/coresight-funnel.c

@@ -86,14 +86,14 @@ static int funnel_enable(struct coresight_device *csdev,
 	bool first_enable = false;
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
-	if (atomic_read(&in->dest_refcnt) == 0) {
+	if (in->dest_refcnt == 0) {
 		if (drvdata->base)
 			rc = dynamic_funnel_enable_hw(drvdata, in->dest_port);
 		if (!rc)
 			first_enable = true;
 	}
 	if (!rc)
-		atomic_inc(&in->dest_refcnt);
+		in->dest_refcnt++;
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
 	if (first_enable)
@@ -130,7 +130,7 @@ static void funnel_disable(struct coresight_device *csdev,
 	bool last_disable = false;
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
-	if (atomic_dec_return(&in->dest_refcnt) == 0) {
+	if (--in->dest_refcnt == 0) {
 		if (drvdata->base)
 			dynamic_funnel_disable_hw(drvdata, in->dest_port);
 		last_disable = true;

drivers/hwtracing/coresight/coresight-replicator.c

@@ -126,15 +126,15 @@ static int replicator_enable(struct coresight_device *csdev,
 	bool first_enable = false;
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
-	if (atomic_read(&out->src_refcnt) == 0) {
+	if (out->src_refcnt == 0) {
 		if (drvdata->base)
 			rc = dynamic_replicator_enable(drvdata, in->dest_port,
 						       out->src_port);
 		if (!rc)
 			first_enable = true;
 	}
 	if (!rc)
-		atomic_inc(&out->src_refcnt);
+		out->src_refcnt++;
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
 	if (first_enable)
@@ -180,7 +180,7 @@ static void replicator_disable(struct coresight_device *csdev,
 	bool last_disable = false;
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
-	if (atomic_dec_return(&out->src_refcnt) == 0) {
+	if (--out->src_refcnt == 0) {
 		if (drvdata->base)
 			dynamic_replicator_disable(drvdata, in->dest_port,
 						   out->src_port);

drivers/hwtracing/coresight/coresight-tpda.c

@@ -190,10 +190,10 @@ static int tpda_enable(struct coresight_device *csdev,
 	int ret = 0;
 
 	spin_lock(&drvdata->spinlock);
-	if (atomic_read(&in->dest_refcnt) == 0) {
+	if (in->dest_refcnt == 0) {
 		ret = __tpda_enable(drvdata, in->dest_port);
 		if (!ret) {
-			atomic_inc(&in->dest_refcnt);
+			in->dest_refcnt++;
 			csdev->refcnt++;
 			dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", in->dest_port);
 		}
@@ -223,7 +223,7 @@ static void tpda_disable(struct coresight_device *csdev,
 	struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
 	spin_lock(&drvdata->spinlock);
-	if (atomic_dec_return(&in->dest_refcnt) == 0) {
+	if (--in->dest_refcnt == 0) {
 		__tpda_disable(drvdata, in->dest_port);
 		csdev->refcnt--;
 	}

include/linux/coresight.h

@@ -200,8 +200,8 @@ struct coresight_connection {
 	struct coresight_device *dest_dev;
 	struct coresight_sysfs_link *link;
 	struct coresight_device *src_dev;
-	atomic_t src_refcnt;
-	atomic_t dest_refcnt;
+	int src_refcnt;
+	int dest_refcnt;
 };
 
 /**